Walk the Sunset Down
by Lomonaaeren
Summary: HPSS preslash. Severus drinks an age regression potion. Suddenly Potter is a lot more understandable. COMPLETE.


**Title: **Walk the Sunset Down

**Disclaimer: **J. K. Rowling and associates own these characters. I am writing this story for fun and not profit.

**Pairings: **Harry/Snape pre-slash

**Rating: **PG-13

**Warnings:** A bit of angst, some fluff, age regression

**Wordcount: ** 5000

**Summary: **Severus drinks an age regression potion just to see what will happen. And after that, the experiment continues.

**Author's Notes: **Another of my Advent fics, for josiedanger, who requested Severus either drinking an age regression potion or Harry getting thrown back into the Marauders era. I went with a fic idea that's a little more pre-slash than slash. Happy Advent!

**Walk the Sunset Down**

It was finished.

Severus tapped his stirring rod on the edge of the cauldron and lowered it slowly to the table beside it, not taking his eyes from the cauldron itself.

When no puff of white smoke came out of the cauldron, and no drop of red leaped over the rim of it, Severus nodded and walked around the edge of the table to fetch a vial. He noticed his hands were shaking when he reached that point. He bowed his head and stood in silence for a few seconds until he was sure that he could pick up the vial and dip it into the potion without spilling it, or dropping it, or doing something else stupid and undignified.

When he had the vial full of potion in front of him, Severus held it up against the light. When he checked, it was the flawless color of liquid rubies, and there was no thread of green or any other shade in it. Severus nodded slowly. Good. He had brewed it correctly, and it would function correctly when he drank it.

_If _he drank it.

Severus felt his mouth tighten. This was one of the potions that he had learned about but never brewed in his Potions mastery, and then he'd never had time to attempt it when he was teaching in Hogwarts before the war, consumed with his memories of Lily and the potions that Dumbledore and Pomfrey required of him whenever he wasn't teaching. Since the war, he could not say that he had found _peace_, but the memories were not as consuming, and Albus was not here to make demands.

_To think that one day I would be grateful for that._

Severus banished the thought, and went back to studying the potion. There was no one and nothing nearby to test it on, if he did not try it himself. This potion would not work on animals, although a similar and less expensive potion was available for making beloved pets younger. He could not ask anyone to take it, because there was no one to volunteer. Severus might be left alone since the war, with people reluctantly believing he had done as Albus asked because of the Unbreakable Vow, but that was a far cry from having a friend who would agree to act as a test subject.

_You know that you intended to take it all along._

Severus grimaced. And then there was the times that he could wish his own _mind _was less clever.

He tilted his head back, and eased the vial closer and closer to his mouth. There was a long moment when he thought he might drop the vial, or the potion might be too viscous to drip out when he thought it would. Then the light flashed through the potion again, and a few drops fell out like drops of Veritaserum.

Severus discovered that he was holding his breath, and snorted in disgust at the same moment as the potion touched his tongue. This was not the biggest moment of his life, no matter that his body had chosen to act as if it was.

The taste of the thick liquid was as bloody as the red color promised. Severus closed his mouth and swallowed, copper echoing the motion of his tongue. For a moment, he felt the dart of warmth that pierced down to his stomach, and wondered if he was stupid to have tried this, not because the potion would harm him but because so many of its effects were ordinary so far.

Then he bent double, and barely managed to put the vial on the table in time, as the heat grew between his legs, churning, and in his stomach turned to a revolving pool of liquid. The coppery taste filled his mouth to such a great extent that Severus thought he would throw up. It was difficult to keep track of the sensations and take mental notes the way he always did when working with the first doses of an experimental potion.

Then again, he could take note of those potions more easily when watching their operation from outside on animals and plants.

The coppery taste swirled around again, and rose to his head like a fountain. Severus reached out with trembling hands, and managed to seize the edge of the table. He blinked, hard, ignoring the sensation that the blood vessels in his eyes were bursting, and focused on the hands that gripped the table.

It was _not _his imagination, he thought, caught somewhere between triumph and fear. His skin was already tauter on the back of his hands, without the scars and faint burns that were the marks of a lifetime spent in Potions mastery. His eyes could perceive, more quickly, that his fingernails had also shrunk and changed, lost some of their thickness and consistency. There was no pattern of veins on the back of his hands, no sensation of sharpness where his knuckles pressed against his skin.

He lifted his head, and looked into the mirror that he had deliberately placed, ready for this moment, on the other side of the lab.

His own face peered back at him, but his face the way he remembered it from occasional glimpses during his last year at Hogwarts: pale, yes, but sharper, more furtive. This was the face of a young man who had never learned to hide his thoughts yet, a man with a different arrangement of muscles and skin.

But although he had additional keenness of sight, and, Severus thought, brilliancy in the eyes, nothing could hide the shadows of experience he had acquired. The potion changed only the body, not the personality or the emotions. Severus was glad of that. He had no desire to experience the same uncertainty about taking the Dark Mark that he had experienced during his first seventh year, or his uncontrollable passion for Lily.

Then he nearly fell over as something _else _hit his blood, something that was not like emotion but so near to it that for long moments, Severus could only experience it as passion. A second later, he understood, and straightened up with a hiss and a grimace.

_Hormones. _He knew they were part of the body, not purely emotional, but somehow, he had not connected the ideas of an age regression potion that would return his body to its teenage state and the near-constant arousal he felt right now.

Severus grimaced and managed to stand straight at last, casting a Transfiguration on his too-roomy clothes so that they became more constricting on his limbs but looser around his groin. He wanted no irritation on what felt like sensitive skin there.

Severus took a deep breath and glanced at the door to his lab. The only way to test that the potion had worked the way he wanted it to, as far as changing all the parts of his body back, was to leave the dungeon and get physical exercise of the sort that pacing back and forth in the limited space here would not afford him.

It was dawn, or a little after. He had finished the potion at sunrise, as the brewing instructions said he should. With the dose he had consumed, he would have until sunset to enjoy himself.

_That still is not very much time. _

Severus was grateful for the voice of his mind this time, as he strode across the floor of the lab with less grace but more speed than he had used in years, and flung the outside door open. A seventeen-year-old wizard with a thirty-nine-year old voice in his head was less likely to get into the scrapes so common to most wizards of his age.

* * *

"_Snape_?"

Severus grimaced and turned around on his broom. He had already tested his body with many simple tasks such as brisk walking, running, and a swim in the lake. He had never been particularly good on a broom, however, and was already regretting his attempt at trying whether acquired knowledge, in this case, could make up for non-perfect reflexes.

Never had his regret been this great, however. Because Harry Potter was hovering on a broom beside him, gaping at him, and being able to see all the way down his throat had never been one of Severus's ambitions.

"You know that Minerva warned some of the students I might brew an age regression potion," Severus said, and frowned a little. One of the things he should have tried out before now was his voice. It was less haughty and _much _less intimidating than he had wanted it to be.

A teenager's voice, in fact. But Severus had not particularly missed that aspect of being a boy.

Potter shook his head, blinked once, and seemed to readjust. He had been doing that, since the war. It made Severus hate him, but there was little that did not. What was _particularly _unfair was that Potter had been adjusting quickly to not getting every little privilege that had been afforded to him before the war. Which meant he didn't complain about extra detentions, and didn't spend as much time bullying the Slytherin students, and accorded Severus a quiet respect that baffled him.

"Right." Potter shrugged one shoulder, looked him over once more, and then shook his head. "I didn't know you played Quidditch."

"I am only doing it to test my reflexes," Severus said haughtily, and shifted on his broom. He grimaced as it made his traitorous groin flare up again. He really would have to change the composition of the potion and see if there was any way to make the effect of the hormones less strong. "I never wanted to play Quidditch when I was your age."

Potter only blinked behind his glasses and nodded. "Right," he repeated. "See you later." He turned his broom towards the far side of the pitch.

Severus leaned forwards. "Wait!" A second later, as Potter twisted back, light as a dandelion puff on the wind, he cursed the impulsiveness that was apparently also part of the potion.

"Yes?" Potter asked.

Severus gritted his teeth, but he had begun now, and there was no going back. "Race me. I want to test my reflexes, I told you."

"You said that you weren't good at Quidditch."

Severus let his nostrils flare, back on more comfortable ground now. "And you would never play anyone who wasn't good at Quidditch, of course. I should not have asked." He was careful turning his back on Potter, since one wrong move here would make him easily spin out of control.

"It's not that," Potter told his back. "I don't want to humiliate you."

Severus turned around again to stare at him, and Potter looked elsewhere as the broom spun further than Severus had meant to, so that he ended up facing Potter in profile. Severus cursed aloud, not caring-who was Potter going to report him to?-and finally steadied it so that he was facing Potter square on. "Since when do _you _care about humiliating _me_?" he asked. "You _live _to humiliate me."

"No," Potter said quietly, and met Severus's gaze square on as well. "That was my father."

Severus stared back, his throat working. He was furious, embarrassed, and more intrigued than he liked to admit. His own emotions and memories mixed with the ones induced by the potion, and ensured that he kept quiet long enough for Potter to finish speaking.

"I know that my dad was horrible to you. But I'm not the same way. I'm trying to _show _you that I'm not, by leaving you alone and doing what you tell me in class." Potter raked his hand through his hair once more. "Anyway. I don't think this is going to work. But I don't want to race you. The broom would dump you on the ground." Again he turned as if he was going to fly to the far side of the Quidditch pitch.

"Coward," Severus dared him softly.

Potter froze, staring off into the distance. Then he let loose a shuddering breath and rubbed the broom shaft with one hand. "I promised McGonagall and Ginny and Hermione that I wouldn't get into a fight with you," he said.

"You promised the Headmistress, who has no authority over me, and a girl you are no longer dating, and a girl whose academic knowledge outpaces her emotional knowledge, that you would not engage in combat with me," Severus said, and let his voice drawl out the words. "They said nothing about a race, did they?"

Potter paused one final moment, then turned around with a fluid grace that Severus had to admire. "No," he said. "They didn't."

Severus saw the muscles bunching in Potter's shoulders and thighs, his hands clenching on the broom, and smiled.

He was not caught by surprise when Potter shot forwards, but he was surprised by the direction he went. Severus was already flying straight up, in order to have the advantage of the sun behind him. Potter dipped low, heading straight for the other side of the Quidditch pitch, and rose and soared back and forth in a mocking blur of speed.

Severus raised his hands, hanging on with his knees, and drew his wand. He let his broom have its head while he cast a charm at Potter's.

The broom bucked underneath him. Potter rose with it, still hanging on with both hands and both knees as though riding a horse, and then yell-laughed back at him, "I'm already familiar with that one, Snape!"

He turned upside-down, then in a corkscrew, so wild that Severus's charm flew off. Severus tensed for the retaliation that was sure to come, but it seemed Potter was only intent on winning the race.

Severus growled and kicked at his own broom again. He had wanted to test his reflexes, hadn't he? Well, and his impulsiveness. Taking his hands off the broom was something he would never have done as an adult.

But as an adult, he didn't have the eyes and ears and recklessness to enjoy the burst of speed after Potter, either, the dips he was making himself because he wasn't much in control of the broom but he could best keep it from crashing that way, and the way that he nearly touched Potter's bristles before Potter shot ahead of him and slapped his hand against the pole of the Keeper's hoop.

"I _win_," Potter declared, turning around to look at him.

Severus blinked. He had never seen Potter this close before when he had finished a race, and he could admit, if only to himself, that Potter was right. He had less of James in him than Severus had supposed. His eyes were dancing with pure enjoyment of the challenge, no gloating, and eyes of that color were still ones that Severus knew how to read better than anyone else's in the world.

He seemed to have stared too long. Potter cocked his head. "What is it?"

Severus shook his head and cleared his throat. "So you won the race, but do you assume that you will win a duel?"

"That's fighting," Potter began, looking absurdly back towards the school, as though he expected Minerva to pop out and condemn him any second.

"Nonsense," Severus said, as softly and persuasively as he could. "It is fighting within regular rules, and I promise you that I will not use any spells I did not know in my seventh year. That should keep it fairer."

Potter examined him for one second more, that intense, stripping gaze, and then nodded. "But it has to be somewhere no one will see and stop us."

"I have the place," Severus replied, and led the way back to the ground, to return the brooms, and then show Potter what he _could _do.

* * *

"It makes a good dueling practice room."

Severus sneered and turned around. He was on the far side of the great arena that the Room of Requirement had turned itself into on his request, one with empty stone stands, a packed floor of hard earth, and various weapons and props lying about, including ropes, knives, lengths of chain, shards of ice, and stones.

"This is not a dueling practice room," he said, and began to walk in a slow circle, his eyes on Potter. He had asked for a room where they could duel each other without killing or shedding too much blood, and so he knew that the Room itself would probably act to restrict some spells or attacks. But that didn't matter. He was still looking forward to seeing what he and Potter could come up with.

And he was enjoying the looseness with which his limbs moved, the absence of creaks in his knees, the utter freedom from the pain and pull of old wounds.

"What is it, then?" Potter asked, drawing Severus's attention back to him.

Severus _did _have to catch his breath for a second. Potter had moved so he could keep an eye on Severus, but hadn't shifted his ground much other than that, even with Severus's circling. He was looking at him, and his eyes were so patient, and plainly green, and so _direct, _that Severus licked his lips before he could stop himself. Sometimes it was easy to divorce Potter from his eyes and think only of their color.

Potter flushed deeply.

Then there were other times that it was hard to think of Potter as the _real _owner of those eyes, the one Severus had been familiar with, he decided abruptly. Lily would have rolled her eyes at him and made some sly remark. Potter looked as if he'd like to bolt out of the door at his own reaction.

"A dueling arena," Severus contented himself with saying. "Any of these objects can be used as a weapon." He gestured with his wand at the nearest several.

Potter's head turned with the movement, and Severus jerked his wand down, making a hard ball of wrapped rubber and leather fly at Potter.

Potter ducked his head so fast that Severus thought he saw an afterimage, and created a Shield Charm in front of him that ricocheted the ball back against the wall. Severus barely dodged.

"Practice over the summer," Potter said, answering his unspoken question without seeming to pause for breath. "And expertise at Defense." The minute he finished the sentence, his next spell, a tangling silver rope of light and fire that Severus hadn't seen for a long time, was flying at him.

Severus had to duck, but the rope simply bounced off the wall like the ball had and came back at him. Finally, he remembered the countercurse, when it was a second from frying him, and murmured it. The silver rope frayed along its length with dark spots and disappeared a few centimeters from his face.

He turned back to find Potter _smirking_.

Severus promptly launched a barrage of curses, all of which he had indeed known in his seventh year, but many of which were ones he had invented, and others which were Dark Arts he had learned from his fellow young Death Eaters. He could hear himself screaming as he did it. His face was red, and his blood was pumping, and his hands were clenched when he didn't need to relax his fingers to create a wand movement.

Potter leaped and twirled like a bloody ballet dancer avoiding some of Severus's spells. One got through, one that flung Potter to the floor and dragged him along it, so that he rose with smears of blood and grit on his cheeks. But even then, Potter only raised Shield Charms and kept trying to Disarm Severus.

It made Severus _furious_.

"Why don't you _use _Dark Arts?" he yelled back, as they ran around the room like madmen. Severus had used another spell to raise the knives and chains from the floor and make a hail of them flying at Potter, but he deflected them with shields that Severus had not known could be so flexible and potent. "I know you can! I heard about you using the Cruciatus Curse on Carrow!"

"I prefer to cheat!" Potter yelled back.

Severus opened his mouth to question that, and then went down, hard. When he hadn't been looking, Potter had strung a chain in front of him, rigid in the air at knee-height. Severus slammed his head into the stone as he fell, and grunted. A quick charm that he performed without thought told him there was no concussion.

He managed to roll over, but by that time, Potter was straddling his chest, panting into his face.

"Do you surrender?" Potter asked, and held his wand to his throat.

Severus hesitated long enough to make Potter push the wand at him harder. That had been what Severus was waiting for. He cleared his throat. Potter leaned near, as if that would make him more likely to hear words of yielding.

Severus drove his knee sharply upwards, and when Potter was done panting and bending and groaning, Severus had his wand in the appropriate place, too. He could feel Potter shift a little, trying to remove Severus's wand from dangerous proximity to his injured cock without giving up his control over Severus.

"Stalemate?" Potter asked a second later, sounding hopeful.

Severus stared back at him through a red haze of rage. He thought the only way he might be angrier was if Potter had tried to knee _him_ in the groin.

Potter only waited, his eyes hard and patient at the same time. He seemed to think it was a stalemate no mater how much Severus decided otherwise, so he finally cleared his throat and answered, grudgingly. "I won."

"By the same sort of cheating I used," Potter agreed. "But I'm still holding you down with my wand to your throat, so I'm not sure how much of a _win _that really is."

Severus growled. "A Golden Gryffindor, cheating? I'm not sure that I can stand the shock."

"The Hat _did _want to put me in Slytherin." Potter tossed his hair out of his eyes. He was still panting, and apparently ignoring the small trickle of blood making its way down his cheek as well as the way Severus held the most precious part of his body hostage. "I reckon now we know why."

Severus must have gasped too deeply at the ridiculous revelation-the _lie_, it had to be-because Potter suddenly drew back, and moved off Severus, and he lost the connection of his wand to Potter's groin. Then Potter skipped around him and held his wand to Severus's throat again.

"This time, _I _won," Potter said.

Severus glared up at him and said the first thing that came into his head. (Really, he would have to get this teenage impulsiveness part drained out of the potion). "I thought you said that your point wasn't to humiliate me?"

The fun left Potter's face, as though it was light someone had shut a door on. He drew back and turned away. Severus rose to his hands and knees, eyes on Potter's back, trying to understand why this had ended the contest. Not that he really objected to it doing so, he had to admit. He rubbed his throat gingerly.

"It wasn't," said Potter. "And if it did, then I let this go on too far. I'm sorry."

Once again, he began walking away, the way he had almost flown away from Severus on the pitch. Severus supposed the Room might let him go, too. The door had been charmed to lock until the duel was done, like a true dueling arena, but the duel was done.

"Wait," he said again, standing this time and dusting off the stone grit from his trousers. At least his voice sounded calm and normal.

Potter glanced at Severus over his shoulder, his eyes alien and distant. "Why?"

_Not because he's upset at me, _Severus promptly decided. _Because he's upset at himself._

He sighed and shook his head. "Come with me."

* * *

This time, they ended up out by the lake, where they sat beside the water, and Potter watched him sideways, not even trying to hide that he was doing it, the way he would in class. Then again, Severus supposed that he looked too different at the moment for Potter to be bothered by the usual state of affairs between them.

_Obviously, or he would not have dueled with me or flown with me._

"What did you want to talk about?" Potter had hunched over his knees, as though his belly hurt. His hands lay hidden somewhere beside him, plucking at grass or throwing stones. Severus felt the usual trickle of irritation. if Potter would only _apply _himself, the way he had in the duel, the way he did at Quidditch, then he would do better at all his subjects, not just Defense.

He dammed the trickle and said, "You assumed that I wanted to speak with you about something?"

Potter hunched over further. He said nothing.

Severus understood after a moment, and stifled a sigh-groan of his own. If he didn't have something to talk about, then Potter would stay silent until the moment when Severus signaled Potter could leave. He no longer laid himself out the way he had at the beginning of the day, telling Severus things he had never wanted to know.

Severus scowled at the lake. Along with the impulses and the hormones came a good deal of perception, of interest in other people he had never wanted to have. He knew why. When he was seventeen, interpreting other people's masks and gestures and words had been a matter of life and death, as he negotiated his new place in the Death Eaters. It seemed the potion affected his mind and memories more than he had thought it would.

But he was no longer a Death Eater. There was, at the moment, no Mark on his arm.

"Listen," he told the water. "I am angry at you. You are not your father or your mother, but I am still angry at you. You took chances with your life that you never should have. You annoyed me more than you should have. You _sneaked into my Pensieve_."

He became aware that Potter was staring at him sidelong, and sneered a little. "What? Will you deny your responsibility for that crime as well? Or is it the fact that you do not see it as a crime?"

"No," Potter said. "It's just-_took chances with my life? _When I was going to have to die _anyway_? You're upset about that?"

"I did not know until the year before you died that you would have to," Severus said back, and closed his eyes. He almost wished that he had never begun this conversation. He wished that he could have let Potter walk or fly away from him earlier in the day.

"I'm sorry for sneaking into your Pensieve," said Potter. "And as for annoying you, I think that was mutual."

Severus snapped his eyes open. "You still did not need to _do it so often_." His voice cracked, and he felt a suspicious stinging at the edges of his eyes. He did not raise his hand to wipe at them because that would only draw Potter's attention to them. _Stupid teenage body_.

"I know," Potter said simply. "But you didn't need to pick on me and assign me detention as often, either."

Severus opened his mouth to say something about the necessary cover for a spy, but Potter looked hard at him. "I know you did _some _of it because you enjoyed punishing me. Admit it."

Severus sniffed a little, and finally nodded his head. "Perhaps I did," he said. "That does not mean that I did not have legitimate grievances."

"I've tried to give you space because of that." Potter looked at him intently. "Why did you decide that you wanted to spend today with me? You could have been alone while you were young the same way you have as an adult."

Severus stared out over the lake. The sun was sliding towards the horizon. He grimaced a little. It _had _been a whole day in Potter's company, without many of the experiences that he had promised himself.

But perhaps he could take advantage of these moments of honesty, while he was literally not the man who had tormented and been tormented by Potter all these years.

"I became young to see what would happen," he said, shutting his eyes. "I spoke to you, dueled with you, flew with you, came here to talk to you, to see what would happen. I have no better answer than that. I am sorry if you feel-used."

He could never have said that to Potter if he was adult. It would never slip _out _if he was adult. He was glad that he had the excuse of a younger face and mind to say it now.

Potter was silent. Then Severus felt the last thing he had expected, a hand on his shoulder. He started and turned his head, ready to draw his wand if Potter did not accept the only apology he was willing to offer.

Potter's face was near him, his eyes studying Severus's face so intently that Severus felt seared. He did not pull away, but it was a severe effort that kept him where he was.

"Thank you," Potter said at last, quietly. "I don't feel used. I feel-I don't know. That things are different now, at least."

Severus wanted to sneer, to say that things were only different for as long as the potion lasted. That he couldn't duel Potter or fly with Potter or talk with Potter this way when he was once again a professor.

But he turned to look at the sunset again, and heard Potter ask, "How long does the potion last?"

"Until the sun sets," Severus murmured.

"Good," Potter said.

Severus looked hard at him. Potter smiled and shifted a little nearer along the bank to sit with him. He looked at the sunset, too, guiding Severus's eyes back there almost insensibly.

"I want to see what happens next," Potter said, and took his hand.

**The End.**


End file.
